CONSTANT DIFFERENTIAL GROWTH-RATIOS 21 



Values of Constant Differential Growth-ratios for Shoot- 

 weight against Root-weight in Various Plants (from Pear- 

 sail, 1927) (Fig. 4) 



Values of Cell-diameter and Nuclear Diameter in the Oocytes 

 of Hydractinia Echinata, in /i. (From Teissier, 1927) 



k = 0-69 ; b — 1-5 



Mean Values of Pre-ocular Length and Total Length in Planaria 

 gonocephala, calculated from Abeloos (1928) 



k — 0-63 approx. 



Total length . 1-5 3-0 50 18-0 mm. 



Pre-ocular length . 0-231 0-43 0-50 1-125 mm. 



Mean Values for Facet-Number in the Two Lobes of Bar-eyed 

 Drosophila at Different Temperatures (from Hersh, 1928) (Fig. 12) 



In both cases k for ventral lobe on dorsal lobe is about 1-5, 

 but the value of b is considerably higher for the homozygotes. 



